<template>
  <div class="goods">
    <div class="menu-wrapper" ref="menuWrapper">
      <ul>
        <li :class="{current: currentIndex===index}" class="menu-item" v-for="(item, index) of goods" :key="index" ref="menuList" @click="selectMenu(index, $event)">
          <span class="text border-1px">
            <span v-show="item.type>0" class="icon" :class="classMap[item.type]"></span>{{item.name}}
          </span>
        </li>
      </ul>
    </div>
    <div class="foods-wrapper" ref="foodsWrapper">
      <ul>
        <li class="food-list food-list-hook" v-for="(item, index) of goods" :key="index" ref="foodList">
          <h1 class="title">{{item.name}}</h1>
          <ul>
            <li @click="selectedFood(food, $event)" v-for="(food, index) in item.foods" :key="index" class="food-item border-1px">
              <div class="icon">
                <img width="57" height="57" :src="food.icon" />
              </div>
              <div class="content">
                <h2 class="name">{{food.name}}</h2>
                <p class="desc">{{food.description}}</p>
                <div class="extra">
                  <span class="count">月售{{food.sellCount}}</span><span>好评率{{food.rating}}</span>
                </div>
                <div class="price">
                  <span class="now-price">¥{{food.price}}</span><span class="old-price" v-show="food.oldPrice">¥{{food.oldPrice}}</span>
                </div>
                <div class="cartcontrol-wrapper">
                  <cartcontrol :food="food" @increase="increaseFood"></cartcontrol>
                </div>
              </div>
            </li>
          </ul>
        </li>
      </ul>
    </div>
    <shopcart
      ref="shopcart"
      :delivery-price="seller.deliveryPrice"
      :min-price="seller.minPrice"
      :selectFoods="selectFoods"
    ></shopcart>
    <food :food="selectFood" ref="food" @increase="increaseFood"></food>
  </div>
</template>

<script type="text/ecmascript-6">
import BScroll from 'better-scroll'
import Shopcart from '@/components/shopcart/shopcart'
import Cartcontrol from '@/components/cartcontrol/cartcontrol'
import Food from '@/components/food/food'

const ERR_OK = 0

export default {
  name: 'Goods',
  props: {
    seller: {
      type: Object
    }
  },
  data () {
    return {
      goods: [],
      listHeight: [],
      scrollY: 0,
      selectFood: {}
    }
  },
  components: {
    Shopcart,
    Cartcontrol,
    Food
  },
  computed: {
    currentIndex () {
      for (let i = 0; i < this.listHeight.length; i++) {
        let height1 = this.listHeight[i]
        let height2 = this.listHeight[i + 1]
        if (!height2 || (this.scrollY >= height1 && this.scrollY < height2)) {
          this._followScroll(i)
          return i
        }
      }
      return 0
    },
    selectFoods () {
      let foods = []
      this.goods.forEach((good) => {
        good.foods.forEach((food) => {
          if (food.count) {
            foods.push(food)
          }
        })
      })
      return foods
    }
  },
  methods: {
    selectedFood (food, event) {
      if (!event._constructed) {
        return
      }
      this.selectFood = food
      this.$refs.food.show()
    },
    selectMenu (index, event) {
      if (!event._constructed) {
        return
      }
      let foodList = this.$refs.foodList
      let el = foodList[index]
      this.foodsScroll.scrollToElement(el, 300)
    },
    increaseFood (target) {
      this._drop(target)
    },
    _drop (target) {
      this.$nextTick(() => {
        this.$refs.shopcart.drop(target)
      })
    },
    _initScroll () {
      this.menuScroll = new BScroll(this.$refs.menuWrapper, {
        click: true
      })
      this.foodsScroll = new BScroll(this.$refs.foodsWrapper, {
        click: true,
        probeType: 3
      })
      this.foodsScroll.on('scroll', (pos) => {
        if (pos.y <= 0) {
          this.scrollY = Math.abs(Math.round(pos.y))
        }
      })
    },
    // 得到一个包含每一个部分的高度的数组
    _calculateHeight () {
      let foodList = this.$refs.foodList
      let height = 0
      this.listHeight.push(height)
      for (let i = 0; i < foodList.length; i++) {
        let item = foodList[i]
        height += item.clientHeight
        this.listHeight.push(height)
      }
    },
    _followScroll (index) {
      let menuList = this.$refs.menuList
      let el = menuList[index]
      this.menuScroll.scrollToElement(el, 300, 0, -100)
    }
  },
  created () {
    this.classMap = ['decrease', 'discount', 'special', 'invoice', 'guarantee']

    this.$http.get('/api/goods')
      .then((response) => {
        response = response.body
        if (response.errno === ERR_OK) {
          this.goods = response.data
          this.$nextTick(() => {
            this._initScroll()
            this._calculateHeight()
          })
        }
      })
  }
}
</script>

<style lang="stylus" rel="stylesheet/stylus" scoped>
@import '~@/common/stylus/mixin.styl'
.goods
  display: flex
  overflow: hidden
  position: absolute
  top: 174px
  bottom: 46px
  width: 100%
  .menu-wrapper
    flex: 0 0 80px
    width: 80px
    background-color: #F3F5F7
    .menu-item
      display: table
      height: 54px
      width: 56px
      line-height: 14px
      padding: 0 12px
      &.current
        position: relative
        z-index: 10
        margin-top: -1px
        font-weight: 700
        background-color: #FFF
        .text
          border-none()
      .text
        display: table-cell
        width: 56px
        vertical-align: middle
        border-1px(rgba(7, 17, 27, .1))
        font-size: 12px
        .icon
          vertical-align: top
          display: inline-block
          width: 12px
          height: 12px
          margin-right: 2px
          background-size: 12px 12px
          background-repeat: no-repeat
          &.decrease
            bg-image('decrease_3')
          &.discount
            bg-image('discount_3')
          &.guarantee
            bg-image('guarantee_3')
          &.invoice
            bg-image('invoice_3')
          &.special
            bg-image('special_3')
  .foods-wrapper
    flex: 1
    .title
      padding-left: 14px
      height: 26px
      line-height: 26px
      border-left: 2px solid #D9DDE1
      font-size: 12px
      color: rgb(147, 153, 159)
      background-color: #F3F5F7
    .food-item
      display: flex
      padding: 18px
      border-1px(rgba(7, 17, 27, .1))
      &:last-child
        border-none()
        margin-bottom: 0
      .icon
        flex: 0 0 57px
        margin-right: 10px
      .content
        flex: 1
        .name
          margin: 2px 0 8px 0
          font-size: 14px
          color: rgb(7, 17, 27)
          line-height: 14px
          height: 14px
        .desc, .extra
          color: rgb(147, 153, 159)
          line-height: 10px
          font-size: 10px
        .desc
          line-height: 14px
          margin-bottom: 8px
        .extra
          .count
            margin-right: 12px
        .price
          font-weight: 700
          line-height: 24px
          .now-price
            margin-right: 8px
            font-size: 14px
            color: rgb(240, 20, 20)
          .old-price
            text-decoration: line-through
            font-size: 10px
            color: rgb(147, 153, 159)
        .cartcontrol-wrapper
          position: absolute
          right: 12px
          bottom: 12px
</style>
